My son is doing a grade 5 science fair project - he was hit by a car 2 years ago, so now is very interested in learning how cars could be made to follow tracks and stops if it encounters an obstacle with sensor technology. His experiment is not to learn how to write all of the code, but just to understand how you build it and the components involved and their functions. He has built the smart robot car on his own and is wanting to have the code to do both line tracking and obstacle avoidance to test different line tracking patterns and if it stops with different size of obstacles that the smart car encounters. We are using the codes that came with the set he has bought and it has line tracking and obstacle avoidance codes separately but he wants them combined. It is a 4WD elegoo smart robot 3.0 - box set - uno controller board V5 sensor expansion board, servo and cloud platform Gp2Y0A21 distance sensor to rotate 180 degrees, ultrasonic sensor module (distance measurement and obstacle avoidance), line tracking module - black and white sensor for recognition of the white and black lanes.
We got the codes working separately so he knows he built it correctly. Here is the code we tried to combine .... its not working at all - it does not track lines and does nothing but stop when it reaches an obstacle.
with the obstacle avoidance program - it stops at obstacle and turns and keeps going until it reaches a new obstacle. With line tracking it follows the track.
I am pretty sure it will need some code to search out the line after it avoids the obstacle but have no idea how to write that.
your help and guidance to my 10 year old would be great!
#include <Servo.h> //servo library
Servo myservo; // create servo object to control servo
int Echo = A4;
int Trig = A5;
//Line Tracking IO define
#define LT_R !digitalRead(10)
#define LT_M !digitalRead(4)
#define LT_L !digitalRead(2)
#define ENA 5
#define ENB 6
#define IN1 7
#define IN2 8
#define IN3 9
#define IN4 11
#define carSpeed 150
int rightDistance = 0, leftDistance = 0, middleDistance = 0;
void forward(){
analogWrite(ENA, carSpeed);
analogWrite(ENB, carSpeed);
digitalWrite(IN1, HIGH);
digitalWrite(IN2, LOW);
digitalWrite(IN3, LOW);
digitalWrite(IN4, HIGH);
Serial.println("go forward!");
}
void back(){
analogWrite(ENA, carSpeed);
analogWrite(ENB, carSpeed);
digitalWrite(IN1, LOW);
digitalWrite(IN2, HIGH);
digitalWrite(IN3, HIGH);
digitalWrite(IN4, LOW);
Serial.println("go back!");
}
void left(){
analogWrite(ENA, carSpeed);
analogWrite(ENB, carSpeed);
digitalWrite(IN1, LOW);
digitalWrite(IN2, HIGH);
digitalWrite(IN3, LOW);
digitalWrite(IN4, HIGH);
Serial.println("go left!");
}
void right(){
analogWrite(ENA, carSpeed);
analogWrite(ENB, carSpeed);
digitalWrite(IN1, HIGH);
digitalWrite(IN2, LOW);
digitalWrite(IN3, HIGH);
digitalWrite(IN4, LOW);
Serial.println("go right!");
}
void stop(){
digitalWrite(ENA, LOW);
digitalWrite(ENB, LOW);
Serial.println("Stop!");
}
//Ultrasonic distance measurement Sub function
int Distance_test() {
digitalWrite(Trig, LOW);
delayMicroseconds(2);
digitalWrite(Trig, HIGH);
delayMicroseconds(20);
digitalWrite(Trig, LOW);
float Fdistance = pulseIn(Echo, HIGH);
Fdistance= Fdistance / 58;
return (int)Fdistance;
}
void setup(){
Serial.begin(9600);
pinMode(LT_R,INPUT);
pinMode(LT_M,INPUT);
pinMode(LT_L,INPUT);
pinMode(Echo, INPUT);
pinMode(Trig, OUTPUT);
pinMode(IN1, OUTPUT);
pinMode(IN2, OUTPUT);
pinMode(IN3, OUTPUT);
pinMode(IN4, OUTPUT);
pinMode(ENA, OUTPUT);
pinMode(ENB, OUTPUT);
stop();
}
void loop() {
if(LT_M){
forward();
}
else if(LT_R) {
right();
while(LT_R);
}
else if(LT_L) {
left();
while(LT_L);
}
myservo.write(90); //setservo position according to scaled value
delay(500);
middleDistance = Distance_test();
if(middleDistance <= 20) {
stop();
delay(500);
myservo.write(10);
delay(1000);
rightDistance = Distance_test();
delay(500);
myservo.write(90);
delay(1000);
myservo.write(180);
delay(1000);
leftDistance = Distance_test();
delay(500);
myservo.write(90);
delay(1000);
if(rightDistance > leftDistance) {
right();
delay(360);
}
else if(rightDistance < leftDistance) {
left();
delay(360);
}
else if((rightDistance <= 20) || (leftDistance <= 20)) {
back();
delay(180);
}
else {
forward();
}
}
else {
forward();
}
}
